Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people, just like you, are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions

Rounding Whole numbers

Posted on 2011-09-21
Last Modified: 2012-05-12
I'm having a hard time rounding. I pull a quantity from a stored procedure and need to round this number up. It will be used as the MaximumScale number for a Excel chart. I never know legth (number of digits it will be) examples:

2300 needs to be 2500
2500 needs to be 3000
234000 needs to be 250000 and so forth.
Been trying to use Math.Ceiling and Math.Floor.

Math.Ceiling(Qty / Num) * num
But not sure how to determine num or is there a better way.
Question by:MadIce
  • 7
  • 5

Expert Comment

ID: 36576799

Math.Round(Qty / num) * num could work for you, where num is the "rounder".


double qty = 2300;
double num = 500;
double result = Math.Round(qty / num) * num;

that would give you 2500.

I hope it is useful.

Best Regards,

Author Comment

ID: 36576828
That would probably work if I can determine what num should be. num could be 5, 50, 500, 5000, 50000 and so forth. How can I determine that number?
LVL 37

Expert Comment

by:Neil Russell
ID: 36576847
That dont help with the 3rd example.

num needs to be 5 * 10^( the length of qty in digits -2)

I think?

Free Tool: Postgres Monitoring System

A PHP and Perl based system to collect and display usage statistics from PostgreSQL databases.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

LVL 37

Expert Comment

by:Neil Russell
ID: 36576979
Very quickly in excel so you can visualise.....

 Formula in excel
LVL 37

Expert Comment

by:Neil Russell
ID: 36577041

Dim Qty as Double = 243000D
Dim StrQty as String = Qty.ToString("D")
Dim LenFactor as Integer = StrQty.Length() - 2

Dim Answer = math.ceiling(Qty+1,5*10^LenFactor)

Think that works but not on a machine with .net on right now.

Open in new window


Author Comment

ID: 36577113

I get an error for math.ceiling. doesn't except this many arguments

Author Comment

ID: 36577222
OK, got part of it.

Dim Qty as int32 = spReturnNum   'Say it = 27105
dim num as int32 = (Math.Log10(Qty)) - 1
dim qt as int32 = Math.Ceiling(Qty) + (5 * 10 ^ num)

This gives me 32105 but what I really need is 32000.
The (5 * 10 ^ num) part has helped.
LVL 37

Accepted Solution

Neil Russell earned 500 total points
ID: 36577262
Ok so .net ceiling is different, ny bad....

Dim Answer = math.Round((Qty+1)/(5*10^LenFactor)) * (5*10^LenFactor)


Author Comment

ID: 36577381
That's very close but can round down. I never want to round down.
LVL 37

Expert Comment

by:Neil Russell
ID: 36577520
Dim Answer = math.Round((Qty+ (5*10^LenFactor) -1 ) / (5*10^LenFactor)) * (5*10^LenFactor)

LVL 37

Expert Comment

by:Neil Russell
ID: 36577524
Hmmm no, Grrrrrr
Bloody .NET!
LVL 37

Expert Comment

by:Neil Russell
ID: 36577575
Or will it..... lol

Its 01:00 here and my eyes have gone! Good luck, bed time.

Author Closing Comment

ID: 36581513
I believe what I have below is working. The (5 * 10 ^ num) part really helped
Thanks alot.

Dim Qty As Int32 = SPGetQty
Dim Num as Int32 = (Math.Log10(Qty)) - 1
Dim answer As Int32 = (Math.Round((Qty) / (5 * 10 ^ num)) * (5 * 10 ^ num))

If Qty >= answer Then
    answer += 5 * 10 ^ num
End If

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

We all know that functional code is the leg that any good program stands on when it comes right down to it, however, if your program lacks a good user interface your product may not have the appeal needed to keep your customers happy. This issue can…
Calculating holidays and working days is a function that is often needed yet it is not one found within the Framework. This article presents one approach to building a working-day calculator for use in .NET.
This video shows how to quickly and easily add an email signature for all users on Exchange 2016. The resulting signature is applied on a server level by Exchange Online. The email signature template has been downloaded from: www.mail-signatures…
With Secure Portal Encryption, the recipient is sent a link to their email address directing them to the email laundry delivery page. From there, the recipient will be required to enter a user name and password to enter the page. Once the recipient …

809 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question